Piezoelectric ceramic-material

ABSTRACT

A PIEZOELECTRIC CERAMIC MATERIAL IS PROVIDED CONSISTING ESSENTIALLY OF SOLID SOLUTION OF THE THREE COMPONENTS PB(MN1/3Z2/3)O3, PBTIO3 AND PBZRO3, WHEREIN Z REPRESENTS ONE ELEMENT SELECTED FROM THE GROUP CONSISTING OF NB, TA, SB AND BI.

Oct. 1 7, 1972 NoRxo rsuaoucm ET AL 3,699,045

PIEZOELECTRIC CERAMIC-MATERIAL Filed Dec. 22. 1967 i 8 Sl'xeecs-SheefI 1 035' es; 0a;

fr 4s A+ if@ l para, 0.20 am 0.60 0.80 mmm/M5510:

,ab (Mm/J Nz/oa vFlcal FIG.3

INVEIVORS v Nan/o T51/saucy] 1.45.40 ramal-usm Tous. oHA/o By rsf/Nea A164511/ Oct. 17, 1972 NoRlo TsUBoucHl ET AL 3,699,045

PIEZOELECTRIC CERAMIC -MATERIAL 0.00' d'2@ 0.20 also 0.80 oo F 2 b Jua/s417025 Noe/o rsuaacw/ MASA@ mmf/,45M

7001641/ OIM/0 OCLW, 1972 NoRlo TsuBouciHl ETAL 3,699,045

PIEZOELECTRIC CERAMIC -MATERIAL Filed Deo. 2z, 1967 s sheets-sheet 5 H6270. 0.20 0.40 0.60 0.80 ,n/ng Tada,

PbVnyj 7222/3/03 FIGA Pb Tf' 03 I Pbzr 0. P60120, ra zw,

F 6 INVEN T025' Oct. 17, 1972 Filed Deo. 22, 1967 NoRlo TsuBoucl-u ET AL 3,699,045

PIEZOELECTRIC CERAMIC-MATERIAL 8 Sheets-Sheet TOMEJ/ OHNO TSUNEO AHA SHI 06f 17 1972 NoRlo TsuBoucl-ll ET AL PIEZOELECTRIC CERAMIC-MATERIAL Filed Dec. 22, 1967 8 SheeS-Sheei"l 5 FIG. 7

Pb (Nn//J S 23203 F IG 9 v INVENI'ORS' I PZr 0.3

Oct. 17, 1972 NoRlo TsuBoucl-n ETAL 3,699,045

PIEZOELECTRIC CERAMIC -MATERIAL J/VVE/V 70.05 F IG. 8 b 02200 202200:,

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A rroaw rs 0d. 17, 1972 NoRlo TSUBOUCHI ET AL 3,699,045

PIEZOELECTRIC CERAMIC-MATERIAL )VOR/0 TSUBOUCH/ #7445.40 TAKAHASH/ TOMEJ/ OH/VO 75l/NEO A K457i/ E A Trae/V575' United States Patent O 3,699,045 P'IEZOELECTRIC CERAMIC-MATERIAL Norio Tsubouchi, Masao Takahashi, Tomeji Ohno, and Tsnneo Akashi, Tokyo-to, Japan, assignors to Nippon Electric Company, Limited, Tokyo-to, Japan Filed Dec. 22, 1967, Ser. No. 692,739 Claims priority, application Japan, Dec. 29, 1966, 42/971, 42/972, 42/974, 42/21,108, 42/25,273, 42/25,274, 42/49,623, l2/56,175

Int. Cl. C04b 35/46, 35/48 U.S. Cl. 252-62.9 5 Claims ABSTRACT F THE DISCLOSURE A piezoelectric ceramic material is provided consisting essentially of a solid solution of the three components Pb(Mn1/3Z2/3)O3, PbTiO3 and PbZrO3, wherein Z represents one element selected from the group consisting of Nb, Ta, Sb and Bi.

This invention relates to piezoelectric materials and more particularly to novel piezoelectric ceramics having excellent piezoelectric properties.

Fundamental measures for evaluating in practice the piezoelectric properties of a piezoelectric material are the electromechanical coupling factor and the mechanical quality factor. The former is a representative of the efficiency of transforming the electric oscillation into mechanical vibration and of conversely transforming the mechanical vibration into electrical oscillation. Greater electromechanical coupling factor stands for better eficiency of interconversion. The latter shows the reciprocal proportion of the energy consumed by the material during the energy conversion, larger mechanical quality factor accounting for smaller energy consumption.

One of the typical elds of application of piezoelectric materials is manufacture of the elements of ceramic filters. In this case, it is necessary to furnish the electromechanical coupling factor with an optimum value selected from a wide range between an extremely great value and a very small value and it is desirable for the mechanical quality factor to assume as large a value as possible. This fact is fully described in, for example, R. C. V. Macaria, Design Data for Band-Pass Ladder Filter Employing Ceramic Resonators which appears in Electronic Engineering, vol. 33, No. 3 (1961), pp. 171-177.

The transducer elements of mechanical lters provide another important field of application of piezoelectric ceramics. In this case, both the electromechanical coupling factor and the mechanical quality factor should be as large as possible.

It has been often true, however, that conventional piezoelectric ceramics, for example, barium titanate (BaTiO3) and lead titanate zirconate [Pb(TiZr)O3] have the electromechanical coupling factor and the mechanical quality factor one or both of which is of extremely small value and hence they are unfit for the practical use. In particular, the mechanical quality factor has often been so small as to make the practical use of the ceramics impossible. Attempts have been made to improve these factors by incorporating various additional constitutents into the ceremics such as lead titanate zirconate ceramics but in most cases have resulted in improvement of only one of electromechanical coupling factor and mechanical quality factor. Thus, these two factors have not remarkably improved simultaneously.

'Ihe object of this invention is to provide a novel piezoelectric ceramic material having large values of both the electromechanical coupling factor and mechanical quality factor.

The other object of this invention is to provide a novel piezoelectric ceramic material suited for use in various fields such as manufacture of the elements of ceramic filters and the transducer elements of mechanical lters.

This invention is based on the new discovery that the ceramic compositions consisting essentially of a solid solution of Pb(Mn1/3Z2/3)O3-PbTiO3-PbZrO3 ternary system, where Z represents one element selected from Nb, Ta, Sb, and Bi, show the excellent piezoelectric properties and hence have the practical utility.

The above ceramic compositions contain lead (Pb) as a divalent metallic element and also titanium (Ti) and zirconium (Zr) as tetravalent metallic elements. Moreover, the element manganese (Mn) and one element selected from niobium (Nb), tantalum (Ta), antimony (Sb), and bismuth (Bi) are contained in such a proportion that they may be, as a whole, substantially equivalent to a tetravalent metallic element.

In case that niobium (Nb) is selected for Z and that the ceramic material of the ternary systems is represented by the compositional formula where x, y and z represent a set of mol ratios of the cornponents and x+y+z=l.010, it has been found that the compositions should be restricted, in view of their effective properties, within the range determined by the following combination of the sets of mol ratios x, y and z:

z y z 0. 10 0. 80 0. l0 0. 01 0. 7l 0. 28 0. 01 0. 09 0. 90 0. 10 0. 0l) 0. 90 0. 60 0. 00 0. 40 0. 60 O. 30 0. 10

Also, when tantalum (Ta) is selected for Z, the effective range of the ceramic compositions given by the formula where x-l-y-|-z=1.00, should be within the range dened by the following combination of the sets of mol ratios x, y, and z:

0. 01 0. 55 0. 44 0. 01 0. 09 0. 90 0. 05 0. 05 0. 90 0. 20 0. 05 0. 75 O. 50 0. 23 0. 27 0. 30 O. 50 0. 20 0. l0 0. 70 0. 20 0. 05 0. 70 0. 25 0. 02 0. 68 O. 30

Where antimony (Sb) is selected for Z, the effective range of the ceramic compositions given by the formula where x-l-y-l-z: 1.00, is decided by the following combination of the sets of mol ratios x, y and z:

z y z Moreover, where bismuth (Bi) is selected for Z, the effective range of the ceramic compositions represented by the formula.

where x--|-y-|z=1.00, is decided by the following combination of the sets of mol ratios x, y and z:

z y z Among the conventional piezoelectric ceramics, known is a ceramic solid solution of the ternary system, which is disclosed in the U.S. Pat.'3,268, 453 granted Aug. 23, 1966, to H. Ouchi et al. This conventional ceramic material, however, does not improve by itself the piezoelectric properties of the previous PbTiO3- PbZrO3 ceramics, and an excellent piezoelectric ceramic material is obtained only by adding thereto at least one of oxides of manganese, cobalt, nickel, iron and chromium as additionalconstituents up to 3 weight percent. In contrast, the ceramic material of ternary system of this invention, where Z represents Nb, Ta, Sb or Bi, remarkably improves the piezoelectric properties by itself (Le. without any additional constituent). This difference in improvement of piezoelectric properties between the conventional compositions and the novel compositions of this invention is, it is believed, due to the fact that the conventional compositions use in the basic composition magnesium (Mg), an element belonging to the Group II-A in the periodic table, in conjunction with a Group V-B element niobium (Nb), while in the compositions of this invention a Group VII-B element manganese (Mn) is used in conjunction with a Group V-B or V-A element niobium (Nb), tantalum Ta), antimony (Sb), or bismuth (Bi).

Excellent piezoelectric properties of the ceramic compositions of this invention will be apparent from the following more particular description of preferred examples of this invention, as illustrated in the accompanying drawmgs.

In the drawings:

FIGS. 1, 4, 7, and 10 are the triangular compositional diagrams of the ternary system showing both the effective ranges of the compositions of this invention and the speciic compositions of the examples;

FIGS. 2(a)(b), 5(a)(b), 8(a)(b), and 11(a)(b) are graphs showing the electromechanical coupling factors [(a)] and the mechanical quality factors [(b)] of both the conventional lead titanate zirconate ceramics and the ceramics of this invention, as a function of compositional change of lead titanate and lead zirconate' in both the ceramics; and

FIGS. 3, 6, 9, and 12 are the phase diagrams of the ternary system of this invention; while FIGS. 1, 2 and 3 are for the novel ternary system Pb (MI11/3Nb2/3 O3PbTiO3PbZI`O3 [among 4the ceramic compositions of this invention;

FIGS. 4, 5 and 6 are for the novel ternary system (`Pb (MI11/3Ta2/3) `O3"PbTiO3-PbZfO3 among the ceramic compositions of this invention;

FIGS. 7, 8 and 9 are for the novel ceramic material of Pb(Mn1/3Sb2/3)O3-PbTiO3-PbZrO3 ternary system of this invention; and

FIGS. l0, 1l and 12 are for the novel ceramic material of Pb(Mn1/3Bi2/3)Oa-PbTiOa-PbZrOa ternary system of this invention.

4 EXAMPLES Powdered materials of lead monoxide (PbO), manganese carbonate (MnCOa), niobium pentoxide (Nb2O`5), titanium dioxide (TiOz) and zirconium dioxide (ZrO2) were used as starting materials to obtain the ceramics of this invention, unless otherwise remarked. These powdered materials were so weighed that the inal specimens may have the compositional proportions shown in Table 1. Also, powdered materials of lead monoxide (PbO), manganese carbonate (MnCOs), titanium dioxide (TiOz), and zirconium dioxide (ZrOZ), and in addition, one tantalum pentoxide (TagO), antimony sesquioxide (Sb2O3) and bismuth sesquioxide (Bi203) were used as starting materials to obtain the ceramics, the Pb(Mn1/3Sb2/3)O3-PbTiO3-PbZrO3 ceramics or the Pb(Mn1/3Bi2/3)O3-PbTiO3-PbZrO3 ceramics of this invention, unless otherwise remarked. These powders were also weighed in such a manner that the final specimens may have the compositional proportions shown in Table 2, 3 or 4. Here, manganese carbonate (MnCO3), antimony sesquioxide (Sb2O3) and bismuth sesquioxide (BiZOS) were weighed as calculated on the basis of manganese monoxide (MnO), antimony pentoxide (Sb205) and bismuth pentoxide (Bi2O5), respectively. In addition the powder of lead monoxide, titanium dioxide and zirconium dioxide were weighed to obtain the conventional lead titanate zirconate ceramics having the compositional proportions shown in Table 5.

The respective powder were mixed in a ball mill with distilled water. The mixed powder were subjected to ltration, dried, crushed, then presintered at 900 C. for one hour, and again crushed. Thereafter, the mixtures, with a small amount of distilled water being added thereto, were press molded into discs of 20 mm. is diameter at a pressure of 700 kg./cm.2 and sintered in an atmosphere of lead monoxide (PbO) for one hour at a temperature specied in tables. Incidentally, the specimens of Pb(Mn1/3Bi2/3)O3-PbTiO3-PbZrO3 system were sintered in an atmosphere of lead monoxide (PbO) and bismuth sesquioxide (Bi203). The resulting ceramic discs were polished on both surfaces to the thickness of one millimeter, provided with silver electrodes on both surfaces, and thereafter piezoelectrically activated through the polarization treatment at C. or at room temperature for one hour under an applied D.C. electric field of 20 to 50 kv./cm. Both the polarizing temperature and electric field actually used are shown in the tables.

After the ceramic discs had been allowed to stand for 24 hours, the electromechanical coupling factor for the vradial mode vibration (kr) and the mechanical quality factor (Qm) were measured to evaluate the piezoelectric activities. The measurement of these piezoelectric properties was made according to the IRE standard circuit. The value of kr was calculated by the resonant to antiresonant frequency method. The dielectric constant (E) and the dielectric loss (tan were also measured at a frequency of 1 kHz. and at a room temperature.

Tables l through 5 show typical results obtained. In fthe tables, the specimens are arranged according to the PbTiO3 content thereof and there are also listed several values of Curie temperature which was determined through measurement of temperature variation in the dielectric constant (e). The novel compositions of the specimens of Tables l, 2, 3, and 4 are shown with black points in FIGS. 1, 4, 7, and 10, respectively, while the conventional compositions of the specimens of Table 5 are indicated by crosses in the same figures.

The results for the specimens Nos. 17 and 18 of Table l, Nos. 10 and 14 of Table 2, Nos. 16, 19 and 2O of Table 3, and Nos. 6 and 8 of Table 4 representatively show that the ceramics of this invention have extremely large values of both kI and Qm. In the specimens Nos. 7, 29 and 39 of Table l, No. 24 of Table 2, Nos. 10, 30 and 35 of Table 3, and No. 18 of Table 4, increase in the Qm value is particularly remarked. Comparison of these results with those for the specimens Nos. 4 and 9 of Table 5 will reveal that the greatest kr and Qm values of the novel ceramics of this invention are far superior to the maximum k,l and Qm values of the conventional lead titanate zirconate ceramics which have been known as the most excellent piezoelectric ceramic material. Moreover, comparison of the results in Table 1, 2, 3, or 4 with those in Table 5, particular-ly between the novel and conventional ceramics in which` the ratios of the PbTiO3 content and the PbZrO3 content are similar to each other, will also indicate that both k, and Qm are remarkably improved in the ceramics of this invention. This latter fact will be more clearly understood from FIG. 2 (a) (b), FIG. 5 (a) (b), FIG. 8 (a) (b), or FIG. 11 (a) (b), wherein the curves of a thick line represent the kr values [(11)] and the Qm values [(b)] of a novel ceramic material containing mol per- Cent Of Pb(MI11/3Nb2/3)O3 2], Pb(MI11/3Ta2/3)O3 [FIG. 5], Pb(Mn1/3Sb2/3)O3 [FIG. 8], or

[FIG. 11], the varying amount v of PbTiO3 and the remaining amount of PbZrO3, while the curves of a fine line show the kr values [(a)] and the Qm values [(b)] of a conventional lead titanate zirconate ceramic material with the varying amount v of PbTiO3.

As is seen from the above, this invention provides the excellent, useful piezoelectric ceramics having the quite large values of Iboth kr and Qm.

In the novel ceramics of Pb(Mn1/3Z2/3)O3PbTiO3 PbZrO3 ternary system (Z is Nb, Ta, Sb, or Bi) of this invention, the superior piezoelectric propenties as mentioned above are available only when the compositions represented by the formula [Pluma/322,3)oaixrrbrioiyrrbzroi,

where x, y and z represent a set of mol ratios and x-|-y+x=1.00 and where Z represents one element selected from Nb, Ta, Sb, and Bi falls within the area A-B-C-D-E-F of FIG. 1 of the drawing in case Nb is seleceted for Z, within the area G-H-IJKLMNO of FIG. 4 of the drawing in case Ta is selected for Z, within the area a-b-c-d-e-f-g of FIG. 7 of the drawing in case Sb is selected for Z, and within the area h-i-i-k-l-m of FIG. 10 of the drawing in case Bi is selected for Z. The sets of mol ratios of the vertices of each area are as follows:

marocco: QWDUHDO In case the Pb(Mn1/3Z2/3)O3 content (Z represents Nb, Ta, Sb, or Bi) of the ternary system ceramic material is less than that falling within the above-mentioned area, it becomes impossible to complete the sintering in manufacture of the ceramics and besides the piezoelectric properties of the ceramics obtained are inferior to or nearly equal to those of the conventional lead titanate zirconate ceramics or otherwise, even if improved, insuicient for practical use. If the Pb(Mn1/3Z2/3)O3 content (Z is Nb, Ta, Sb, or Bi) is more than that falling within the abovementioned area, accomplishment of the sintering is very diicult and the ceramics obtained have not practicable piezoelectric propenties. Where the PbTiO3 content is outside the above-mentioned area, the piezoelectric properties of the ceramics so deteriorate as to make the practical use impossible. Finally, in case the PbZrOa content is less than the effective content falling within the abovementioned area, it follows that completion of the sintering becomes diicult, that the polarization treatment is no-t perfectly carried out and that a useful piezoelectric ceramic material is not obtainable. While, the PbZrOS content more than the effective content results an unuseful piezoelectric ceramic material having markedly inferior piezoelectric properties.

In view of the above, it is determined that the ceramics of this invention, if required to apply to a practical use, should have the compositions falling within any of the areas specified above. The ceramics of the elective compositions show excellent piezoelectric properties an-d have a high Curie temperature, as shown in Tables 1 through 4, so that the piezoelectric activities may not be lost up to elevated temperature.

The ternary system of Pb(Mn1/3Z2/3)O3 (Z represents Nb, Ta, Sb, or Bi), PbTiO3, and PbZrO3 of this invention exists in a solid solution in greater pants of compositions and such a solid solution has a perovskite-type crystalline structure. FIGS. 3, *6, 9, and 12 show the crystalline phases of the ceramic compositions falling within the areas A-B-C-D-E-li` of FIG. 1, G-H-I-J-K-L-M-N-O of FIG. 4, a-b-c-d-e-f-g of FIG. 7, and h-i-j-k-I-m of FIG. 10, respectively, as determined at room temperature by the powder method of X-ray analysis. These compositions have a perovskite-type crystalline structure land belong to either the tetragonal phase (indicated by T in the iigures) or the rhombohedral phase (indicated by R). The morphotropic phase boundary is shown with a thick line in each figure. In general, kr is extremely great for the compositions in the vicinity of this phase boundary, while Qm is extremely large for the compositions remote from this phase boundary.

It will be apparent that the starting materials to be used in manufacture of the ceramics of this invention are not limited to those used in the above examples. In detail, those oxides which are easily decomposed at elevated temperature to form the required compositions may be used instead of any starting material of the above examples, as exemplified by PbaO., for PbO and by MnOz for MnOO3 in the examples. Also, those salts such as oxalates or carbonates may be used instead of the oxides used in the examples, which are easily decomposed into the respective oxides at elevated temperature. Otherwise, hydroxides of the same character as above, such as Nb(OH)5, may be used instead of the oxides such as Nb205. Moreover, an excellent piezoelectric ceramic material having similar properties to the above examples is still also obtainable by separately preparing the powdered material of each Pb(Mn1/3Z2/3)O3 (Z is Nb, Ta, Sb, 0r Bi), PbTiO3 and PbZrO3 in advance and by using them as starting materials to be mixed subsequently.

It is usual that niobium pentoxide (Nb205), tantalum pentoxide (Ta205) and zirconium dioxide (ZrOz) which are available in the market contain, respectively, several percent of tantalum pentoxide (Ta205), niobium pentoxide (Nb205) and hafnium dioxide (HfOZ). Accordingly, the ceramic compositions of this invention are allowed to contain small amounts of such oxides or elements as existing in the materials available in the market. Moreover, it is presumable that addition of a small amount of some additional constituent to the ceramic compositions of this invention may further improve the piezo- 5 electric properties, from the similar fact recognized in the conventional lead titanate zirconate ceramics. It will be understood from the foregoing that the ceramic com- 8 positions of this invention may include appropriate additives.

While there have been described what at present are believed to be the preferred examples of this invention, it will be obvious that various modifications can be made therein without departing from the scope of this invention and that this invention covers all the ceramic compositions as specified in the appended claims.

TABLE 1 Polarizing Sinter- Mol ratio of composition ing Electric Curie temp. Temp eld kr Tan 6 terp. Pb(Mn1/3Nb2/a) Oa, :v PbTiOg, y PbZrO3, z C.) C (kv./cm.) (percent) Qm e (percent) 0. 10 0. 80 0. 10 1, 300 100 50 6 910 210 2. 3 0. 05 0. 75 0. 20 1, 300 100 50 10 1, 870 200 1. 6 0. 01 0. 71 O. 28 1, 300 100 50 4 300 190 1. 6 0. 10 0. 70 0. 20 1, 300 100 50 11 1, 300 250 1. 8 0. 05 0. 65 0. 30 1, 300 100 50 18 3, 700 290 1. 1 0. 01 0. 60 0. 39 1, 300 100 50 210 270 1. 8 0. 05 0. 55 0. 40 1, 300 100 50 33 3, 700 520 1. G 0. 20 0. 55 0. 25 1, 300 100 30 28 1, 800 570 2. 4 0. 05 0. 50 0. 45 1, 300 100 5l) 46 2,010 680 1. 0 0. 10 O. 50 0. 40 1, 300 100 50 44 2, 600 82() 1. 4 0. 10 0. 48 0. 42 1, 300 100 50 47 2, 360 890 1. 2 0. 20 0. 48 0. 32 1, 300 100 30 35 2, 000 810 2. 3 0. 30 0. 48 0. 22 1, 300 r t 40 26 1, 140 640 4. 5 0. 42 0. 48 0. 10 1, 270 r t 30 8 340 630 7. 5 O. 01 0. 47 0. 52 1, 300 100 50 40 180 970 2. O 0. 02 0. 47 0. 51 1, 300 100 50 49 770 1, 180 1. 1 0. 05 0.46 0. 49 1, 300 100 50 61 2,030 630 1. 1 0. 10 0. 45 0. 45 1, 300 100 50 59 1, 900 1, 000 1. 2 0. 05 0.43 O. 52 1, 300 100 50 57 2,270 350 1. 1 0. 10 0.43 A 0. 47 1, 300 100 50 51 2, 340 470 1. 2 0. 20 0. 43 0. 37 30() 100 30 52 1, 000 1, O50 3. 5 0. 01 0. 40 0. 59 1, 300 100 50 31 230 460 3. 5 0. 10 0. 40 0. 50 1, 300 100 50 46 3, 400 370 1. 2 0. 30 0. 40 0. 30 1, 300 r t. 40 44 630 1,050 4. 1 0. 40 0. 40 0. 20 1, 270 r t. 40 32 400 1, 080 8. 2 0. 05 0. 35 0. 60 1, 300 100 50 39 3, 300 280 1. 0 O. 20 0. 35 0. 45 l, 300 100 30 42 2, 400 450 2. 0 0. 01 0. 30 0. 69 1, 300 100 50 20 250 370 3. 3 D. 10 0. 30 0. 60 1, 300 100 50 33 5,000 300 1. 2 0. 20 0. 30 0. 50 1, 300 100 30 37 3, 400 380 1. 8 0. 30 0. 30 0. 40 1, 300 r t 40 33 2, 000 470 3. 3 0. 40 0. 30 0. 30 1, 270 r t 40 27 880 620 5. 8 0. 60 0. 30 0. 10 1, 270 r t. 20 5 250 980 11. 2 0. 05 0. 20 0. 75 1, 300 100 50 17 4, 470 200 1. 1 0. 20 0. 20 0. 60 1, 300 100 30 24 4, 800 340 1. 6 0. 30 0. 20 0. 50 1, 300 r t 40 23 2, 700 420 2. 7 0. 40 0. 2O 0. 40 1, 270 r t. 40 23 1, 500 500 4. 6 0. 05 0. 10 0. 85 1, 300 100 50 10 5,500 180 1. 1 0. 10 0. 10 0. 80 l, 300 100 50 11 6, 300 220 1. 2 0. 20 0. 10 0. 70 1, 300 100 30 15 4, 100 390 1. 5 0. 30 0. 10 0. 60 1, 300 Lt. 40 10 2, 800 550 2. 7 0. 40 0. l0 0. 50 1,270 Lt. 40 14 1,000 460 4. 1 0. 60 0. l0 0. 30 1, 270 1.t. 20 10 0 990 12. 3 0. 01 0. 09 0. 90 1, 300 100 50 6 480 32() 2. 4 G. 05 0. 05 0. 90 1, 300 100 50 7 4, 200 170 1. 6 0. 10 0. 00 0. 90 1, 300 100 50 4 400 250 1. 1 0. 20 0. 00 0. 80 1, 300 100 30 6 1, 800 700 2. 0 0. 40 0. 00 0. 60 1, 270 r.t. 40 8 620 680 4. 6 0. 50 0. O0 0. 50 1, 270 Lt. 30 7 560 970 7. 5 0. 60 0. 00 0. 40 1, 270 Lt. 2D 4 420 1, 030 9. 6

Norm-See footnotes at end of Table 4.

TABLE 2 Polarizing Sinter- Mol ratio o composition ing Electric Curie temp. Temp. field kr Tan temp. Pb(Mn1/aTa2/a) O3, :t PbTiOg, y PbZrOg, z C. C.) (km/cm.) (percent) Q,... e (percent) C 0. O5 0. 70 O. 25 b 100 40 13 1, 380 240 1. 4 0. 10 0. 70 0. 20 b 100 40 16 1, 560 300 1. 6 0. 02 0. 68 0. 30 b 100 40 4 1, 740 240 1. 2 O. 05 0. 60 0. 35 b 100 40 34 2, 120 620 1. 3 0. 20 0. 60 0. 20 b r t. 40 10 1, 280 370 3. 6 0. O1 0. 55 0. 44 b 100 40 18 560 460 2. 0 0. 10 0. 55 0. 35 b 100 40 16 1, 230 530 l. 8 0. 30 0. 50 0. 20 a r t. 30 12 680 570 6. 2 0. 01 0. 48 0. 51 b 100 40 52 190 940 2. 3 0. 05 0. 48 0. 47 b 100 40 54 2, 470 1, 070 1. 1 0. l 0.48 0.42 b 100 40 34 l., 380 640 1. 6 0. 20 0.48 0. 32 b x' t 40 25 1, 010 600 3. 6 0. 02 0. 47 0. 51 b 100 40 47 570 1, 000 1. 5 O. 0. 46 0. 49 b 100 40 59 1, 840 560 1. 1 0. 05 0. 43 0. 52 b 100 40 50 2, 500 380 1. 1 0. 0. 43 0. 47 b 100 40 33 860 540 1. 5 0. 0. 43 0. 37 b r t. 40 29 760 660 3. 6 0. 20 0. 38 0. 42 b r t 40 27 1, 300 530 3. 3 0. 05 0. 33 0. 62 b 100 40 31 850 340 1. 4 0. 0. 33 0. 37 a Lt. 30 19 810 660 5. 0 0. O. 28 0. 32 a 1*.19. 30 14 610 740 5. 3 0. 0.23 0. 27 a r.t. 30 7 150 940 12. 3 0. 05 0. 20 0. 75 b 100 40 18 3, 230 240 1. 5 0. 10 0. 10 0. 80 b 100 40 10 4, 340 225 1. 0 0. 01 0. 09 0. 90 b 100 40 10 820 320 3. 4 0. 05 0. 05 0. 90 b 100 40 8 2, 870 210 1. 6 0. 20 0. 05 0. 75 b nt. 40 4 550 850 3. 1

Noren-See footnotes at end of Table 4.

Curie Tan temp. s (percent) C.)

TABLE 3 Polarizing Sintering Electric tem Temp. field kf C.) C.) (kv./cm.) (percent) Mol ratio of composition Pb(Mm/3Sb2/s) Oa, z PbTiOa, y PbZrOa, z

20936511624. 164715100615895815574711328166 2LLn/LLLLLLLLLoLLLomLLLLLn/MZLILZLZFLZLLZOWZLLQW 5899 71 07117 593199319 2.148631778307178 8 271903545365355554M3413333 1111 l D 0.aaaQQQQQQQaaQQQQQQQQQQQQQUQQQQQQQQQQQQQQ 0.0.Q0.0.0.0.0.0.0.0.0.0.QQQQQQQQQQQQQQQQQQHWQQQUQQQQ Curie Tan temp. e (percent) C.)

TABLE 4 Polarizing Sinteriug Electric temp. Tem field kr C.) C.) (kv./cm.) (percent) No'rE.-See footnotes at end oi Table 4.

54963473114000011721 L3.6.2.2.2.5.2.2.3.7..L2.L7.&&L

,340 C.; (2) in the s, triplumbic s, manganese Tan 5 e (percent) ,260-1,300 C. and b stands for 1,300-1 pecimens with a sole asterisk in their number ng materials; also, for the specimens with double asterisk TABLE 5 Polarizing Mol ratio of Sintercomposition ing Electric tem Tem eld PbTiO3 PbZrO; C.) C.) (kv./om.)l (Percent) Notes to tables 1 through 4.-(1) In the column of sintering temp., a" represents 1 r.t. means room temperature; (3) in manufacture ofthe s instead of lead monoxide (PbO) as one of the starti column of polarizing temp tetroxide (Pb304) was use d dioxide (MnOz) was used instead of manganese carbonate (MnC O3).

N OTR-For the specimens Nos. 1 and 2, the evaluation of piezoelectric activity was impossible.

1 1 What is claimedis: 1. A piezoelectric ceramic material consisting essentially of the composition which is represented by the formula where x, y and z represent a set of mol ratios and x+y+z=1.00 and where Z represents one element selected from the group consisting of Nb, Ta, Sb, and Bi, and which falls within the area A-B-C-D-E-F of FIG. 1 of the drawing where Nb is selected for Z, within the area G-HIJKLMNO of FIG. 4 of the drawing where Ta is selected for Z, within the area a-b-c-d-e-f-g of FIG. 7 of the drawing in case lSb is selected for Z, and within the area h-i-i-k-l m of FIG. 10 of the drawing where Bi is selected for Z, the sets of mol ratios of the vertices of said areas being as follows:

2. The piezoelectric ceramic of claim 1, wherein the composition is represented by the formula [Pb(MI11/3Sb2/a) O3]x[PbT0a]y[PbZIOa]z wherein x, y and z represent a set of mol ratios and x-l-y+z=1.00 and which falls within the area a-b-c-d-ef-g of FIG. 7 of the drawing; the set of mol ratios of the vertices of said area being as follows:

l! 1l Z 3. The piezoelectric ceramic of claim 1, wherein the composition is represented by the formula:

12 wherein x, y and z represent a set of mol ratios and x|y+z=1.00 and which falls within the area h-z'jkl m of FIG. 10 of the drawing; the set of mol ratios of the vertices of said area being as follows.'

I Il Z 4. A piezoelectric ceramic material consisting essentially of the composition which is represented by the formula where x, y and z represent a set of mol ratios and x-i-y-l-z=1.00 and which falls within the area A-B-C-D-E-F of FIG. 1 of the drawing; the sets of mol ratios of the vertices of said area being as follows:

z u z 5. A piezoelectric ceramic material consisting essentially of the composition which is represented Iby the formula References Cited UNITED STATES PATENTS 8/1966 Ouchi et al 252-629 8/1966 Saburi 106--39 9/ 1968 Ouchi et al. 252-623 TOBIAS E. LEVOW, Primary Examiner J. COOPER, Assistant Examiner U.S. C1. X.R. 106-39 R 

